多层建筑结构水平剪扭-竖向地震反应的智能复合隔震控制

本文在提出了“碟形弹簧-橡胶隔震垫”和MR阻尼器组合而成的智能复合隔震系统的基础上，建立了智能复合隔震系统对多层建筑结构“水平剪扭-竖向”地震反应控制的设计计算方法。提出了智能复合隔震系统对建筑结构水平地震反应的模糊半主动控制策略和对建筑结构竖向地震反应的被动控制方法。以一个五层框架结构为例进行了仿真分析。分析结果表明，本文提出的智能复合隔震系统是一种十分简单和有效的隔震系统。它可克服建筑结构常规隔震系统的两个主要缺点，有效地抑制多层建筑结构的多维地震反应。     

球面网壳结构的分段式多维隔震控制

球面网壳结构是典型的大跨度空间结构,地震时水平和竖向地面运动分量对其地震响应的影响均十分显著。为了提高网壳结构的抗震性能,可采用支座型隔震装置形成分段式多维隔震机制。在这类多维隔震体系中,碟形弹簧支座可用于结构的竖向隔震,同时,可将其与适用于水平隔震的摩擦摆(FPS)或SMA-橡胶支座配合使用。基于上述概念设计,提出了水平和竖向隔震装置的构造和计算模型。进而,根据网壳结构多维隔震的动力方程,开展了El Centro波作用下双层球面网壳和单层球面网壳结构多维隔震控制的数值模拟。计算结果表明,多维隔震球面网壳结构的杆件内力、加速度和位移的减振效果能达到50%以上,验证了所提多维隔震技术对保护球面网壳结构免遭地震破坏的有效性。     

碟形弹簧竖向减震体系的分析与研究

对碟形弹簧竖向减震体系利用时程分析方法对其进行动力分析，并输入不同场地、不同频谱的地震波考察其减震效果，验证了碟形弹簧在合理控制其刚度的前提下可以起到有效减小竖向地震的作用。     

SMA三维隔震复合支座单层柱面网壳结构的地震响应

大跨空间结构具有空间跨度大,结构整体刚度大、受力合理、耗材少、重量轻等优点,在世界各地应用前景非常广阔。但在强震作用下,此种结构破坏严重,经济损失惨重。震害经验与理论研究表明地震动是一种复杂的多维运动,只考虑单分量水平地震作用是不够的,还应考虑竖向地震分量对整体结构的影响。在作者研制的SMA-叠层橡胶支座的基础上,针对竖向刚度大、竖向隔震效果不明显的问题,研制一种在上部串联加入碟形弹簧的新型三维隔震支座,并建立一典型的单层柱面网壳结构模型,在输入不同峰值地震动情况下,通过时程反应分析可见,SMA三维隔震支座下结构位移、加速度峰值与普通橡胶支座对比明显降低,时程曲线趋于平缓,典型的杆件轴力也有明显降低,说明了SMA三维隔震复合支座隔震效果更好。     

近场地震作用下大型储罐三维隔震地震响应分析

为研究近场多维地震作用下三维隔震储罐的动力响应,采用ADINA软件建立了15×104 m3储罐的有限元模型,选取弹簧单元模拟三维隔震支座,分别输入水平与竖向的近场地震动,定量分析了其动力响应。分析结果显示:对于大型储罐应当考虑竖向地震作用;三维隔震装置可以有效降低储罐的动力响应,但是对晃动波高无控制效果;近场竖向地震作用下的晃动波高幅值很小,实际工程中可以忽略不计。     

三维隔震连续梁桥近断层地震响应数值分析

以一座多跨连续梁桥为研究对象,根据水平和竖向预期隔震目标,计算确定了三维隔震支座相关力学参数。建立了三维隔震连续梁桥数值仿真模型,通过时程反应分析和数值仿真分析三维隔震多跨连续梁桥的地震反应,验证了三维隔震支座的水平和竖向隔震效果。研究结果表明,作者所提出的三维隔震支座具有适宜的水平和竖向隔震力学刚度和耗能能力。在近断层三维地震动作用下桥墩弯矩隔震效果达60%~70%,近断层脉冲型地震动会造成隔震支座过大的水平剪切变形,进而造成上部结构水平碰撞甚至支座剪切破坏。跨中竖向地震反应隔震效果达20%~40%,菱形钢板阻尼器的应用显著改善了组合碟形弹簧的竖向隔震效果。三维隔震技术是减轻桥梁结构多维地震动反应的有效途径之一,但脉冲型地震动作用可能会降低三维隔震支座的隔震效果,其影响程度和主要影响因素需进一步深入研究。     

一种新型三维隔震支座的试验研究

通过研究三维隔震支座与二维隔震支座力学性能的相关关系,对传统的蝶形弹簧改进,并将改进后的新型蝶形弹簧通过对合叠合的方式组成蝶形弹簧竖向隔震支座,与普通橡胶支座通过串联的方式组合成一个新型的三维隔震支座。对二维天然隔震橡胶支座(LNR)、碟形弹簧竖向隔震支座、三维隔震支座分别进行了水平方向和竖向力学性能试验,分析了独立状态下的二维隔震支座与三维隔震支座相互之间力学性能的关系,并对其规律进行了归纳和总结。试验结果表明:竖向弹簧片支座的竖向刚度随压应力的增加呈线性变化;在低频率情况下频率对其竖向刚度影响不大;三维隔震支座的水平刚度相对于独立状态下的LNR会略有降低;LNR对三维隔震支座的整体竖向刚度的影响不大。     

核电结构三维隔震研究

三维隔震对保护核电厂结构和内部设备设施安全具有重要意义。首先,设计了一种三维隔震控制系统,该系统包括水平隔震层和竖向隔震层,在竖向隔震层中设置抗摇摆装置以达到控制结构摇摆反应。其次,对三维隔震模型进行了振动台试验验证,振动台试验结果表明,该系统能有效减小上部结构地震响应。最后,对核岛厂房采用三维隔震技术进行了讨论,分析了强震作用下核岛厂房三维隔震结构反应特征。     

三维隔震(振)支座的工程应用与现场测试

首先介绍了一种新型三维隔震(振)支座,该支座由联接件、竖向隔振支座和水平隔震支座组成。竖向隔振支座和水平隔震支座具有较小刚度,采用该类型支座的隔震结构,其竖向基频和水平基频可远离地铁、铁路振动和地震的主频,从而实现竖向隔振和水平隔震作用。其次介绍了该三维隔震(振)支座在某一地铁平台上部结构中的应用情况,对该类型支座进行了竖向性能和水平性能试验。最后对三维隔震(振)结构与传统结构进行了地铁运行时结构振动的对比测试。测试结果表明:三维隔震(振)系统对振动的高频信号具有显著衰减效果。     

摩擦-碟簧三维复合隔震支座的性能试验研究

对适用于大跨结构的摩擦-碟簧三维复合隔震支座进行了振动台试验研究,该支座在水平向和竖向分别采用摩擦滑移装置和碟型弹簧隔震。在水平向,试验重点测试了简谐激励和地震动激励下支座的滞回性能,考察了竖向荷载变化及地震动强度对隔震性能的影响,以期为建立水平隔震理论模型提供依据;在竖向,对碟型弹簧的等效阻尼比和等效刚度进行了测试,研究了竖向预压荷载和动力荷载对竖向滞回性能的影响。结果表明,复合隔震支座在水平向和竖向均具有较好的滞回性能,竖向等效阻尼比在0.10～0.15间,且随着预压荷载的增加而增大。     

Fuzzy logic control of bridge structures using intelligent semi-active seismic isolation systems

Passive supplemental damping in a seismically isolated structure provides the necessary energy dissipation to limit the isolation system displacement. However, damper forces can become quite large as the passive damping level is increased, resulting in the requirement to transfer large forces at the damper connections to the structure which may be particularly difficult to accommodate in retrofit applications. One method to limit the level of damping force while simultaneously controlling the isolation system displacement is to utilize an intelligent hybrid isolation system containing semi-active dampers in which the damping coeffic ient can be modulated. The effectiveness of such a hybrid seismic isolation system for earthquake hazard mitigation is investigated in this paper. The system is examined through an analytical and computational study of the seismic response of a bridge structure containing a hybrid isolation system consisting of elastomeric bearings and semi-active dampers. Control algorithms for operation of the semi-active dampers are developed based on fuzzy logic control theory. Practical limits on the response of the isolation system are considered and utilized in the evaluation of the control algorithms. The results of the study show that both passive and semi-active hybrid seismic isolation systems consisting of combined base isolation bearings and supplemental energy dissipation devices can be beneficial in reducing the seismic response of structures. These hybrid systems may prevent or significantly reduce structural damage during a seismic event. Furthermore, it is shown that intelligent semi-active seismic isolation systems are capable of controlling the peak deck displacement of bridges, and thus reducing the required length of expansion joints, while simultaneously limiting peak damper forces. Copyright © 1999 John Wiley & Sons, Ltd.     

Three-dimensional seismic isolation bearing and its application in long span hangars

Based on the seismic response characteristics of space frame structures,a new type of seismic isolation bearing defined as a three-dimensional seismic isolation bearing(3DSIB) is developed in this paper.The bearing offers excellent properties such as multi-dimensional seismic isolation,reasonable rotation capability,good ability to resist lifting load,uncoupled stiffness in horizontal and vertical directions,etc.In the 3DSIB,the horizontal dimension is designed by combining the Teflon sliding device and helical spring,while the vertical dimension is developed by introducing disk springs or helical springs.The mathematical model of the 3DSIB was established and its performance with the critical parameters was tested on a shaking table.Furthermore,the 3DSIB was applied in a 120 m span hangar structure and simulated using SAP2000 software to evaluate its performance in practical structures.The performance of the structures with and without 3DSIB was compared.It is shown that the hangar structure with 3D bearings achieves a better performance.The axial force and acceleration response of the structures with 3DSIB are effectively reduced,while the displacement response of the bearing is within the predetermined range.     

巨-子结构智能隔震体系抗震性能研究

针对巨-子结构隔震体系,在隔震层处或子结构顶部与主结构连接处,施加SMA-压电智能复合阻尼器,从而形成巨-子结构智能隔震体系。本文通过限界Hrovat最优控制算法设计了巨-子结构智能隔震体系的半主动控制器,在此基础上,对巨-子结构智能隔震体系进行了Simulink控制效果仿真分析,同时比较了控制装置安装位置的不同对结构控制效果的影响,并与普通隔震结构的减震效果进行了对比。研究结果表明,智能隔震控制1（隔震层加控制装置）和智能隔震控制2（子结构顶部加控制装置）2种控制方案在控制结构的位移方面效果相差不大。总体而言,智能隔震控制2对于控制子结构单元顶部的绝对加速度效果更为显著,但是相对于普通隔震而言,特别是在控制隔震层位移方面2种方案都具有较好的控制效果。实施智能控制可以有效改善巨-子结构被动控制体系的抗震性能,并能降低隔震结构在遭受强震时由于隔震层出现过大位移导致结构倾覆的危险。     

三维隔震单层球面网壳结构频率相关变阻尼半主动控制

在不同频率特征的地震动作用下,三维隔震单层球面网壳结构隔震层最优阻尼设计不同.文中基于单自由度体系加速度传递率函数,提出一种地震动主频相关的加速度阈值变阻尼半主动控制方法以及地震动主频分区识别方法.基于ABAQUS软件的DLOAD子程序,开展了三维隔震单层球面网壳被动控制与半主动控制有限元计算,对节点加速度、杆件轴力进...     

应用MBC策略的MRD 隔震结构半主动控制

磁流变阻尼器(Magnetorheological Damper,MRD)与隔震垫组成的半主动隔震系统能有效地改善被动隔震系统的性能,消除隔震层因过大变形产生的不利影响。基于市场机制的控制(Market-Based Control,MBC)策略是一种利用自由经济市场来模拟控制系统,用销售商和消费者来代替能量源系统和受控系统,并应用市场中商品的供需规律来完成系统控制能量的分配,实现对受控系统有效控制的策略。本文将MBC策略应用于此种半主动隔震系统,提出了相应的控制策略,实现对MRD电压的实时有效控制。算例分析表明,采用此策略能充分利用MRD的变阻尼特性,使结构振动控制效果显著。     

单跨简支梁竖向振动的磁悬浮半主动控制

由于传统的隔振器需要足够的竖向刚度来支撑上部结构,因而不能隔离竖向振动。为了解决这一问题,本文提出一种新的隔振策略,即磁浮式半主动控制方法,并将这一方法应用于弹性梁弯曲振动的半主动控制。将均质弹性梁简化为一带集中质量的简支梁,导出了控制系统的运动方程,讨论了系统在平衡点的稳定性,应用推广的Runge-Kutta方法,得到了系统在随机地面输入下的加速度响应。结果表明：杆件的初始悬浮位置是磁浮式半主动控制系统的平衡点,且平衡点是L稳定的;磁浮式半主动隔振系统具有类似于软弹簧的性质,与普通的弹性简支梁相比,磁浮式半主动振动控制系统的振动频率较低,加速度响应明显减小,系统具有良好的竖向隔振性能。     

An enhanced base isolation system equipped with optimal tuned mass damper inerter (TMDI)

In seismic base isolation, most of the earthquake‐induced displacement demand is concentrated at the isolation level, thereby the base‐isolation system undergoes large displacements. In an attempt to reduce such displacement demand, this paper proposes an enhanced base‐isolation system incorporating the inerter, a 2‐terminal flywheel device whose generated force is proportional to the relative acceleration between its terminals. The inerter acts as an additional, apparent mass that can be even 200 times higher than its physical mass. When the inerter is installed in series with spring and damper elements, a lower‐mass and more effective alternative to the traditional tuned mass damper (TMD) is obtained, ie, the TMD inerter (TMDI), wherein the device inertance plays the role of the TMD mass. By attaching a TMDI to the isolation floor, it is demonstrated that the displacement demand of base‐isolated structures can be significantly reduced. Due to the stochastic nature of earthquake ground motions, optimal parameters of the TMDI are found based on a probabilistic framework. Different optimization procedures are scrutinized. The effectiveness of the optimal TMDI parameters is assessed via time history analyses of base‐isolated multistory buildings under several earthquake excitations; a sensitivity analysis is also performed. The enhanced base‐isolation system equipped with optimal TMDI attains an excellent level of vibration reduction as compared to the conventional base‐isolation scheme, in terms not only of displacement demand of the base‐isolation system but also of response of the isolated superstructure (eg, base shear and interstory drifts); moreover, the proposed vibration control strategy does not imply excessive stroke of the TMDI.     

Research on semi-active control method of a building structure based on non-smooth control

This study investigates the effectiveness of the non-smooth semi-active control algorithm on suppressing the vibration performance of a building structure subjected to seismic waves. According to the Lyapunov stability theory, it has bene proven that the non-smooth semi-active control algorithm can achieve a finite-time stability of the vibration relative to the isolation layer of a building structure. Through numerical simulation of two buildings with different parameters subjected to the input of a seismic wave, the vibration conditions of passive control, LQR semi-active control and non-smooth semiactive control are compared and analyzed. The simulation results show that the non-smooth semi-active control algorithm has a better robustness and effectiveness in restraining the impact of earthquakes on the structure.     

Recent advances in structural control research and applications in China mainland

Abstrect The recent developments of theoretical research, model tests and engineering applications of structural control in mainland China are reviewed in this paper. It includes seismic isolation, passive energy dissipation, active and semi-active control, smart materials and smart structural systems. It can be seen that passive control methods, such as seismic isolation and energy dissipation methods, have developed into the mature stage in China. At the same time, great progress has been made in active and semi-active control, and smart actuators or smart dampers and smart structural systems. Finally, some future research initiatives for structural control in civil engineering are suggested. Supported by : National Natural Science Foundation of China (Grant No. 50025821)